Dental floss applicators make dental floss easier to use. A dental floss applicator generally provides a frame for holding the floss and means for keeping the floss under tension, some even provide means for storage of floss and means for advancing the floss from the storage area to the positions where the floss perform the cleaning functions.
Among prior art dental floss applicators, the one described in U.S. Pat. No. 4,214,598 has been particularly effective. It has a double-capstan floss-advancing arrangement that enables easy advancing of floss into the cleaning position, the double-capstan mechanism furthermore positively stretches the floss as the floss is advanced. This stretching generates a high tension in the floss for easy insertion into the narrow space between the teeth to be cleaned. One embodiment of that invention has been manufacture by Flossrite Corp. of Fort Wayne, Ind. Effectiveness of that product has been recognized by the American Dental Association (ADA).
However, even the best among dental floss applicators must be improved from time to time. Already certain improvements on the original design has been disclosed in U.S. Pat. No. Des. 275,039 and U.S. Pat. No. 4,512,354.
Further improvements that has been sought after for a long time include: 1) Making the applicator more compact and more attractive in appearance, 2) making the applicator body more rigid, 3) reducing the thickness of the applicator body to reduce production cost, and 4) providing better uniformity of the floss tension.
Some of these improvements have unacceptable side-effects: For example, a very compact and attractive embodiment of the invention was already disclosed in the original patent (U.S. Pat. No. 4,214,598, FIG. 9); unfortunately, it turned out to be very difficult to wind floss onto that particular embodiment of the dental-floss applicator. The floss has to be threaded through a hole; and at some point, it has to be threaded under another part of the floss itself. The difficulty in winding makes this embodiment unacceptable.
In the dental floss applicator manufactured by Flossrite, the body had to be thick to provide the needed rigidity. The body could have been made both thin and rigid if it could have been made hollow, but the specific shape does not allow the part to be easily molded of plastic and be hollow on the inside. And if the body were made hollow (deeply concave) on the outside, then it would be difficult to clean. So the applicator body had to be made thick. The thickness of the applicator body is alos mainly responsible for the sometimes poor uniformity of the floss tension.
It is therefore highly desirable to have a dental floss applicator that combines all the attractive features of the embodiments disclosed in U.S. Pat. No. 4,214,598 without the specific problems. The present invention provide such a dental floss applicator. It is as compact as the embodiment shown in FIG. 9 of the patent, it is even more attractive in appearance, yet it is not at all difficult to wind floss on. The present invention furthermore allows the applicator body to be easily molded out of plastic, hollow on the inside, easy to clean, thin-walled, and rigid.